Re: [flexcoders] Re: need strategy for filtering ArrayCollections in a Cairngorm app

Fri, 09 Jun 2006 16:57:22 -0700

Thanks for trying.  An ArrayCollection will not reflect changes made directly to its source array, so new items pushed onto masterArray do not show up in my views.

-Tom

On 6/9/06, Tim Hoff <[EMAIL PROTECTED]> wrote:

Changes to the masterArray in the ModelLocator should be
automatically reflected in the AC if you use either of the binding
methods I posted. If not, sorry. That's all I have.



-TH

--- In [email protected], "Tom Bray" <[EMAIL PROTECTED]> wrote:
>
> The problem is that changes to ModelLocator.getInstance
().masterArray don't
> update the views' dataProviders. In other words, the
ArrayCollections that
> use masterArray as their source don't know when new items are
added to or
> removed from masterArray. That's why I was thinking that
masterArray would
> actually be masterArrayCollection and I'd bind each of the view's
> dataProvider ACs to it so they could stay in sync. I bound the
master AC to
> the sub ACs using BindingUtils and was surprised to see the filter
function
> on the sub ACs affect the master AC. I posted sample code here:
> http://groups.yahoo.com/group/flexcoders/message/39064?l=1
>
> Thanks again!
>
> -Tom
>
> On 6/9/06, Tim Hoff <[EMAIL PROTECTED]> wrote:
> >
> >
> > Something like this should do the trick:
> >
> > <mx:Script>
> > <![CDATA[
> >
> > import mx.collections.ArrayCollection;
> > import org.ets.main.code.model.ModelLocator;
> >
> > [Bindable]
> > public var viewDataProvider : ArrayCollection;
> > viewDataProvider=new
> > ArrayCollection({ModelLocator.getInstance().masterArray});
> >
> > ]]>
> > </mx:Script>
> >
> > -TH
> >
> >
> > --- In [email protected] <flexcoders%
40yahoogroups.com>, "Tom
> > Bray" <tombray@> wrote:
> > >
> > > Thanks, Tim. That makes sense but there's one limitation I'm
not sure
> > how
> > > to work around. That master Array of users is going to be
constantly
> > updated
> > > by the server to show who's currenlty online. Since an Array
isn't
> > > bindable, how would you propagate changes from that Array to
the
> > filtered
> > > ArrayCollections that use it as their source?
> > >
> > > -Tom
> > >
> > > On 6/9/06, Tim Hoff TimHoff@ wrote:
> > > >
> > > > Hey Tom,
> > > >
> > > > In response to this question and the BindingUtils and
> > > > ArrayCollection.filter question, I offer this suggestion. In
the
> > > > ModelLocator maintain a single master Array of all the
users. Then
> > > > in each instance of your view components, create a new bound
> > > > ArrayCollection (dataProvider), with the master Array as the
> > > > underlying source. Each of the ArrayCollections will have a
> > > > different filterFunction based on the type of view component
that is
> > > > instantiated. Because the ArrayCollections don't actually
contain
> > > > any data, just pointers to the underlying Array, I would
handle the
> > > > ArrayCollections and filterFunctions in viewHelpers. In a
sense,
> > > > you would be creating separate sub-sets of the master Array
in each
> > > > instance of your views. If you preferred, you could maintain
each
> > > > ArrayCollection (Array of ArrayCollections) in the
ModelLocator as
> > > > well.
> > > >
> > > > I hope that this makes sense,
> > > > Tim Hoff
> > > >
> > > >
> > > > --- In [email protected] <flexcoders%
40yahoogroups.com><flexcoders%40yahoogroups.com>,

> >
> > "Tom
> > > > Bray" tombray@ wrote:
> > > > >
> > > > > Say my model has an ArrayCollection of all the users that
are
> > > > > connected to my Flex app. I then have configurable list
views that
> > > > > display different subsets of that collection based on
different
> > > > user
> > > > > properties (gender, age, location, etc.). Multiple views,
multiple
> > > > > filters, all being fed from the same master
ArrayCollection of all
> > > > > connected users. I even want the user to be able to
dynamically
> > > > > create new views with different filters.
> > > > >
> > > > > Unless there's something I'm missing, each view is going
to need
> > > > its
> > > > > very own ArrayCollection that has its own filter function
set up.
> > > > I'm
> > > > > picturing a wrapper class that provides addFilter() and
> > > > removeFilter()
> > > > > methods so that the AC's filter function can traverse an
array of
> > > > > other filters -- kind of a CompoundCommand pattern.
> > > > >
> > > > > Assuming that's part of the correct approach, I want my
master AC
> > > > to
> > > > > pump changes out to the filtering ACs which pump changes
out to
> > the
> > > > > views. Is there a way to make the binding mechanism work
for this?
> > > > > Is there a simpler approach I'm overlooking?
> > > > >
> > > > > Any tips you can send my way would be greatly appreciated.
> > > > >
> > > > > Thanks,
> > > > >
> > > > > Tom
> > > > >
> > > >
> > > >
> > > >
> > >
> >
> >
> >
>


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